A haze of smog hung over the Shanghai International Circuit as practice began this morning.
Nearby factories which are usually instructed to shut down around the time of the race are instead running as normal.
Here are pictures of the cars in the haze in China.
View more F1 pictures
Images ?é?® Ferrari spa/Ercole Colombo, Renault/LAT, Williams/LAT, McLaren, Getty Images/Red Bull, Force India F1 Team, Sauber F1 Team, Team Lotus, Virgin Racing, Motioncompany, Pirelli